In communications systems, and especially repetitive signal systems such as radar and the like, clutter, including background noise and noise in the system, can cause extremely difficult problems in identifying return signals. Clutter is an especially difficult problem in existing sidelobe cancelling circuits because clutter signal strength produces a substantial limitation on jammer cancellation performance. Typical existing sidelobe cancelling circuits (adaptive antenna systems) are disclosed in an article by B. Widrow et al, "Adaptive Antenna Systems", Procedure of the IEEE, Volume 55, Number 12, Dec. 1967; U.S. Pat. No. 3,202,990 entitled "Intermediate Frequency Sidelobe Canceller", issued Aug. 24, 1965; U.S. Pat. No. 3,290,684, entitled "Directional Receving System", issued Dec. 6, 1966; U.S. Pat. No. 4,079,379, entitled "Null Steering Apparatus for a Multiple Antenna Array", issued Mar. 14, 1978; and U.S. Pat. No. 4,070,675, entitled "Power Rejection Apparatus Using a Null Constrained Subarray for MTI Radar Applications", issued Jan. 24, 1978.